Electrical relay



ELECTRICAL RELAY Filed July 17, 1931 Fig.1}

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HIS/Attorney Fatented .ian. 17, I933 UNITED STATES PATENT OFFIC FRED H. WINTER, OF SCHENEOTADY, NEW YORK, ASSIGNOR T0 GENERAL ELECTRIC? COMPANY, A COBPOMTION OF NEW YORK aurora roar. annex Application filed July 17,

My invention relates to electrical relays and particularly to contactmaking voltmeter type relays which are adapted to control electrical voltage regulators.

Regulating systems are often provided with control relays which are arran ed to respond to deviations from normal 0 a condition to be regulated in such a manner as to cause the regulating means to initiate compensating changes in the regulated condition. In some cases, however, the regulated condition is apt to attain an extreme value regardless of anything the regulator can do. In such ,cases it is usually desirable not to have the re ulator try to restore the condition to norma because when of its own accord the regulated condition starts to return somewhere near its normal value the regulating means, being in its position to produce a maximum regulating change in this direction, will then cause a momentary extreme value of the regulated condition in the other direction with the result that a paratus which has its operation aflected by the value of the regu'ated condition is liable to injury.

A specific example of such a situation occurs in the regulation of alternating current feeder circuits by induction voltage regulators which are controlled by contact making voltmeters. In such systems when the voltage of the feeder circuit falls below a normal value, the contact making voltmeter closes a pair of raise contacts which cause the regulator to increase the voltage while when the voltage of the circuit increases above a normal value the contact making voltmeter closes a pair of lower contacts which cause the regulator to decrease the voltage of the circuit. With such an arrangement, when the voltage of the feeder circuit drops to abnormally low values, such as for example, when a short circuit occurs thereon, or when the circuit is o cried, as by the operation of a circuit brea er, the contact making voltmeter will close its raise contacts, which will cause the regulator to go to its maximum boost position. If now the voltage is suddenly returned to approximately its normal value, the regulator being in its maximum boost position will cause an abnormally high voltage to 1931. Serial No. 551,537.

ranged to rob the voltmeter of control when the voltage of the circuit falls below a predetermined value and which cause the regulator to go to its maximum lower position instead of its maximum boost position. These auxiliary contacts are usually operated by a separate low voltage coil.

In accordance with my invention, I provide an improved relay, of the contactmaking voltmeter type, which is so constructed that it will close its lower contacts during very low input conditions to the relay as well as during excess values of input to the relay.

It is an object of my invention to provide a new and improved control relay.

Another object of my invention is to provide a new and improved contact-making voltmeter which is arranged to close its'lower contacts on extremely low voltage as well as on over voltage.

My invention will be better understood from the following description, taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

In the drawing, Fig. 1 illustrates diagrammatically a voltage regulating system embodying specific application of my invention, while Fig. 2 illustrates the operation of the a plication of my invention illus trated in ig. 1 during abnormally low voltage conditions.

Referring now to Fig. 1 of the accompanying drawing, wherein I have shown an up plication of my invention as a contact making voltmeter l which is connected to respond to the voltage of a feeder circuit 2 and which is also connected to control the operation of regulating means illustrated as an induction voltage regulator 3. The induction voltage regulator 3 is arranged to control the feeder circuit 2, which is connected to he snppiied' with energy from a supply circuit 4 which, for example, may be the main bus of a substation. Regulator 3, which is of a type well known to those skilled in the art, consists essentially of a series winding connected in the circuit to be regulated and a shunt winding across the circuit to be regulated, these vvindings being inductive- 1 related and being provided with means f dr varying their inductive coupling, whereby variable degrees of voltage buck or boost are induced in the series winding by the shunt winding. Regulator 3 is operated by the usual reversible servo motor 5, whose direction of operation is controlled by raise and lower contacts 6 and 7 respectively, on contact-making voltmeter 1, by means of suitable control circuits including a source of current supply 8.

Raise and lower contacts 6 and 7 are controlledby'circuit controlling element 9 which is pivotally mounted at 10. This element, or arm, 9 is moved by a power translating device in the illustrated form of an operating magnet 11 having a core 12 which connects to an arm 13 which is also pivotally mounted at point 10. A fairly still resilient connecting means 14 is provided between arm 13 and arm 9. With this arrangement arms 13 and 9 move as a unit when the solenoid core 12 moves up and down in response to increases and decreases respectively in the energization of magnet 11.

In order to make contact making voltmeter 1 close its lower contact 7 when magnet 11 is deenergized below a predetermined low value, I provide a link element 15 which is pivotally mounted at 16 and which cooper ates with arms 9 and 13 by means of pins 17 and 18 which are on arm 9 and link 15 respectively.

The operation of this link arrangement upon no voltage, or abnormall low voltage, conditions is illustrated in F ig. 2. Thus, when the energization of magnet 11 falls below a predetermined low value, the weight of core 12 pulls arm 13 downwardly until it engages pin 18 on link 15, whereby this link is turned counter-clockwise about pivot 16 until it engages pin 17 on arm 9. This action will be such that the turning moment produced by the weight of core 12 will tend to force arms 9 and 13 apart, thereby flexing resilient connecting means 14. As shown, this action will result in the closure of lower contacts 7 when magnet 11 is energized below a predetermined low value. In this way, regulator 3 will be moved to its maximum lower position whenever the voltage of circuit 2 falls below a predetermined minimum low value.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that changes and modifications may be made without departing from my invention and I therefore aim in the a pended claims to cover all such changes an modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In combination, a relay having a circuitcontrolling position, and means associated with said rela for causing it to assume said circuit controlling osition on relatively large changes in input rom a normal input value in one direction and on relatively small changes in input from said normal value in the other direction.

2. In combination, a sensitive normally balanced relay having circuit controlling positions on opposite sides of its balanced position, and means associated with said relay for causing it to assume the same position on relatively large decreases in input that it does on relatively small increases in input.

3. In combination, a circuit controlling element having a pair of circuit controlling positions, a power translating device connected to said element in such a way that said element assumes one or the other of its circuit controlling positions depending upon relatively slight divergences from a normal value of the power input to said device, and means associated with said element and said device for causingsaid element to assume the same circuit controlling position it normally assumes upon a relatively slight deviation from normal of the input to said device when there is a relatively large variation in the opposite direction of the input to said device.

4:. In combination, a circuit controlling element having a pair of circuit controlling positions a power translating device connected to said element in such a way that said element assumes one or the other of its circuit controlling positions depending upon relatively slight divergences from a normal value of the power input to said device and means, including a resilient connection between said element and said device, associated with said element and said device for causing said element to assume the same circuit controlling position it normally assumes upon a relatively slight deviation from normal of the input to said device when there is a relatively large variation in the opposite direction-of the input to said device.

5. In a circuit controller, an operating element, a circuit controlling element connected thereto for movement both in unison therewith and relative thereto, resilient means for normally connecting said elements for movement in unison, and means positioned to maintain a relative displacement between said elements while said operating element is moved to a predetermined operating position.

6. In a circuit controller, a circuit controlling element, and an operating element, connected by relatively stiil resilient means,

whereby they normally act as a unit, and

means operative: in accordance with an extreme condition of said operating element for flexing said resilient connection until said circuit controllin element assumes the same position it woul if said operating element was in its opposite extreme condition.

7. In a circuit controller, an operating element, a circuit controlling element pivoted at a point intermediate its ends to one end of said operating element, resilient means connected between said pivoted end of said operatin element and an end of said circuit controlling element for normally connecting said elements for movement in unison, and means positioned for causing a flexing of said resilient means and actuated in accordance with a predetermined position of said operating element for causing relative movement between said elements.

8. In combination, a pivoted arm, fixed contacts cooperating therewith, a solenoid with a relatively heavy core, resilient connecting means between said core and said arm so that when said core rises one pair of contacts is closed and when said core deproportion of the weight of said core is unsupported by the pull of said solenoid.

9. A contact making voltmeter having raise contacts, lower contacts, a magnet and means including connecting means between said magnet and said contacts whereby a normal excitation of said magnet maintains said contacts open, an over energization of said magnet closes said lower contacts, an under excitation above a predetermined amount closes said raise contacts, and an under excitation of said magnet below said predetermined amount closes said lower contacts.

10. A contact making voltmeter having a contact arm with raise and lower positions, a solenoid magnet for operating said arm, a resilient connection between said arm and said solenoid, said connection being stiff enough to permit said arm and solenoid to move as a unit under normal conditions, and a linkage between said solenoid and said arm whereby the turning moment produced by the weight of said solenoid when it is energized below a predetermined amount causes a flexing of said resilient connection changes in the voltage of said circuit, said' voltmeter having raise contacts and lower 

